Public safety is a big concern for people's daily life. Improvements in roadway and automobile designs have steadily reduced injury and death rates in developed countries. Nevertheless, auto collisions are still the leading cause of injury-related deaths. There are different types of dangerous situations that can cause automobile accidents. For instance, drunk drivers, police involve in high speed chases, emergency vehicles speeding to help others, and even reckless driving may cause life-threatening emergencies on road. As such, there is a need for a warning system for impacted individuals.
Some alert systems exist provide emergency notification over a large area. For example, America's Missing: Broadcast Emergency Response (AMBER) system is an alert system for child abductions. The AMBER alert system broadcasts, usually over the radio, any available information about a missing child and suspected vehicle information if available. An AMBER alert is automatically sent through the Wireless Emergency Alerts (WEA) program that broadcasts the alert to all WEA-enabled mobile devices within range of the cellular carrier towers in a large area without regard to the user's whereabouts. These alerts are often also broadcast over popular radio station to an entire city or county. Another example of existing large scale alert systems are government emergency alerts used for flood or severe weather alerts. These alert systems broadcast a message to all people in a large area indiscriminately and often warn people that are not affected and are therefore inefficient and annoying to people.